public void Load()
        {
            textBoxMaNhap.Text    = invoice.ID.ToString();
            textBoxTongTien.Text  = ExtensionHelper.ChangeToCurrency(invoice.Cost.ToString());
            textBoxNguoiMua.Text  = invoice.NameCustomer;
            textBoxNguoiBan.Text  = invoice.NameManager;
            TextBoxNgayNhap.Text  = invoice.Time_Of_Purchase.Day.ToString();
            TextBoxThangNhap.Text = invoice.Time_Of_Purchase.Month.ToString();
            TextBoxNamNhap.Text   = invoice.Time_Of_Purchase.Year.ToString();
            // initialize the width of columns
            foreach (ColumnHeader column in listViewDetail.Columns)
            {
                column.Width = -2;
            }
            //listViewDetail.Columns[listViewDetail.Columns.Count - 1].Width = 0;
            /////

            List <MedicineInvoiceDetail> details = InvoiceHelper.FindMedicineInvoiceDetails(invoice.ID);
            int i = 0;

            foreach (var item in details)
            {
                ListViewItem listViewItem = new ListViewItem(new string[] { i.ToString(), item.Name_Medicine,
                                                                            item.Amount.ToString(),
                                                                            ExtensionHelper.ChangeToCurrency(item.Cost.ToString()) });
                listViewDetail.Items.Add(listViewItem);
                i++;
            }
        }